Known in the art are terminal devices capable of connecting a terminal device owned by a first player and a terminal device owned by another player via communication means to thereby share a game play space. As a mode for sharing play space, it has been disclosed that attack information is generated on the basis of operation on a touch panel provided to the terminal device of the first player and is transmitted to another terminal device connected via the communication means; and meanwhile, similar attack information is received from the other terminal device and predetermined game parameter values are controlled on the basis of the attack information (Patent Document 1).